DE1155230B - Process for the production of a composite laminate - Google Patents

Description

Process for the production of a composite laminate It is known To combine metals with thermoplastic materials to create objects which preserve the strength, stiffness, etc. of the metals, but also at the same time possess the corrosion resistance, transparency, etc. of the plastics. It was too a number of uses have already been found, some of which are noteworthy are important and commonly used, such as the laminates, which are made of steel or aluminum sheet and plasticized polyvinyl sheets, or the reinforced panels made of non-plasticized polyvinyl chloride, which is a enclosing perforated sheet steel. Until now it has been used for similar purposes a stretched metal net has not yet been proposed. This metal net will by elongating a previously with transverse incisions or cutting lines, which alternate with provided sheet metal. That way will a network with rhombic openings obtained, which after pressing directly can be used. The production of the stretched nets is extraordinary easy and economical process, which is continuous with high production capacity can be carried out.

The arrangement of this network between two layers of one possibly transparent thermoplastic material is not particularly difficult if that Plastic material has an overall thickness which is greater than that of the metal sheet. But since the thickness of the stretched metal sheet, especially when it is used as The support element is always on the order of a few millimeters the amount of plastic material required thereby inevitably causes such high costs that such items are only used for a few special fields of application can be used.

An attempt could now be made to make thin sheets of plastic material with the help of suitable application systems on one or both sides of the stretched To use sheet metal.

The application on a single side, however, requires the use of adhesives, which are difficult to use, and besides, the metal side remains exposed to the effects of corrosion.

The application on both sides brings various inconveniences with it, for example, the possibility that the sheets of plastic material through the sharp edges of the stretched net are damaged, the difficulty to bring the plastic sheets continuously into the cavities of the stretched net, as a result of the relative irregularity of the meshes, the practical impossibility of the plastic sheets to adhere to the stretched net at all its points bring, as well as other inconveniences.

It is also already known to use plastic sheets or plates with reinforcing inserts made of fabrics, metal wire, etc., optionally two finished plastic films can converge between two pressure rollers while the reinforcement layer runs axially in the nip between the plastic films and the position of the latter in relation to the plastic film is secured by partition walls is.

The invention now relates to a method for producing a Composite laminate made of a metal net and two thin plastic layers surrounding it with particularly expedient definition of the position of the on a thermoplastic plastic film applied metal net.

The method is characterized in that to secure the position Metal net against the foil is magnetically attracted and that in itself known Way a layer of a vinyl resin dispersion in a plasticizer or a Layer of such a dispersion, diluted with liquid solvents, or a Layer of a synthetic resin powder on the possibly preheated Metal mesh applied and that of the foil, metal mesh and dispersion application formed laminate until the applied vinyl resin gels or solidifies and heat-treating its union with the film.

The mesh can be flattened or corrugated or according to any given Shape to be shaped. In order to rest the metal mesh on the thermoplastic film let, this is put on a magnetic plate, which be flat or can have the desired shape.

If necessary, the deformation of the thermoplastic film can be carried out prior heating can be facilitated. A plastisol or organosol layer is then applied applied to it by one of the known methods, for example by spraying, Rolling, brushing, spraying or the like. Plastisol is the dispersion of a vinyl resin understood in a plasticizer and under organosol a similar dispersion, which is diluted with a certain amount of volatile solvents. It can too Solutions, aqueous suspensions or powders of thermoplastic materials are used be, depending on the properties of these solutions or dispersions od. Like. Selects appropriate methods.

To control the amount of material that is applied to the net and to facilitate its even distribution and thereby avoid that If the mass runs down too much along the vertical parts, this can affect the thermoplastic Material arranged network advantageous before spraying on the plastisol or organosol be heated. This heating can advantageously be carried out with the aid of an infrared radiant panel be performed; however, any other suitable system can be used will.

The heating temperature can fluctuate within fairly wide limits, for example between 50 and 1200 C, but it must be taken into account that by increasing the temperature a faster gelation, thus less runoff and thus thicker and less smooth layers of material are obtained. The gelling properties of the plastisol or organosol and their content of hard or plasticizers other variables, creating the thickness, appearance, stiffness and other properties the coating layer can be determined.

It is interesting that, according to this method, part of the plasticizer can migrate from the coating layer into the layer of the base film. As known, there are overflowing and non-overflowing plasticizers, and this can Appearance can be kept within desired limits.

Since the migration takes place on the lower side of the plastics, which is in contact with the metal net, it can be beneficial to keep this inside to keep more moderate limits, as this gives a better thickness of this layer which is later exposed to shocks or the like.

Spraying is carried out as described above. The sprayed one Layer undergoes thermal treatment at temperatures between 140 and 1700 C for a time ranging from 2 to 10 minutes for every 0.1 mm thickness.

The conditions of this treatment can be within still wider limits sway when in place of plastisols or organosols aqueous resin solutions or dispersions or the like. Can be used.

The gelling or hardening creates an effective adhesion between the plastic film and the sprayed-on layer obtained, thereby stretching the Metal net completely enclosed between the two layers and thus against chemical and atmospheric corrosion is protected.

The process can also be carried out continuously, for example if one starts from a thermoplastic film and a stretched network and unwinds both rolls or even if the net is being used during its manufacture or its deformation treated accordingly.

Depending on the composition of the thermoplastic film and after the composition of the coating layer can have different levels of transparency, different Coloring, etc. can be obtained.

The composite laminates according to the present invention have therefore the same or better properties than the stretched metal net itself on which properties are a function of thickness, mesh size and size and shape of the cavities.

In addition, the properties of the transparency of the laminate from the surface of the cavities and from the transparency of the layers of the used Depending on the plastic material. The laminate is resistant to chemical and atmospheric corrosion, has an attractive appearance and can be without noticeable To be subject to changes within a wide temperature range, namely between -20 and +800 C, can be processed.

The shear strength and scratch resistance is the same as that of the one used Plastic material, and although this is generally not exactly outstanding, is they are sufficient for the intended purposes.

The water adsorption is practically zero, and so the material is completely impermeable. The laminate is dielectric if the raw material is polyvinyl chloride was used, fireproof and sound-absorbing.

The corrugated embodiment can be used as a very good replacement or counterpart used for corrugated sheets made of asbestos cement or galvanized iron sheet.

The following examples are intended to illustrate the present invention, but without this being restricted to this.

Example 1 An unplasticized and unpigmented sheet made of polyvinyl chloride with a thickness of 0.4 mm, 840 mm wide and 1210 mm long, is placed on a slightly larger metal plate (which can be cooled) and under which or in which a system of permanent or electromagnets is arranged is brought.

On this arch is a stretched steel mesh with a thickness of 3 mm, a length of 1200 mm and a width of 800 mm so applied that the plastic film protrudes at least 20 mm over the steel mesh.

The drawn web is heated to about 1000 C, and then on will be a layer of vinyl plastisol which is appropriate for the application at hand Properties related to viscosity, hardening and has transparency, applied with the help of a spray gun.

Because the desired results are achieved with a lot of compositions more detailed information in this regard should be unnecessary.

After a plastisol layer with an average thickness of 0.3 mm was applied, is cured or gelled for 3 minutes at 1600 C, the protruding edges of the vinyl layer beforehand along the circumference of the stretched Metal net had been folded.

With a work cycle of approximately 6 minutes, a laminate is created obtained in the dimensions of 800X 1200 X 3.5 mm and a weight of approximately 3.8 kg, which is suitable for direct use as a roof element, partition wall, protective wall, etc. suitable.

Example 2 The procedure described in Example 1 is similar worked, but the thermoplastic film consists of low-pressure polyethylene, the heating to 1600 C is carried out, polyethylene powder instead of plastisols is used and curing is carried out at 2000 ° C for 2 to 5 minutes.

Example 3 The procedure described in Example 1 is similar worked, but preheating to 1400 C, the plastisol is first sprayed on and then using a brush or flexible nylon bow to remove the excess and the final gelation is carried out as in Example 1 above.

Example 4 The procedure is similar to the previous examples, however, the rigid thermoplastic film and the stretched network according to one determined th shape can be preformed, the mold used for preforming can also be used for the final deformation of the laminate.

Example 5 The laminate is made according to one of the preceding examples produced, but using a roller instead of a surface and wherein both the lower thermoplastic film and the steel mesh continuously from Rolls are unwound or continuously fed from the generating units will. In this way, the composite laminate can be produced continuously will.

Claims (1)

PATENT CLAIM: Process for the production of a composite laminate, consisting of a metal net and two thin layers of plastic surrounding it, in which a metal net is placed on a thermoplastic plastic film and this is secured in its position with respect to the film, characterized in that for Securing the position of the metal net against the foil is magnetically attracted and that in in a manner known per se, a layer of a vinyl resin dispersion in a plasticizer or a layer of such a dispersion, diluted with liquid solvents, or a layer of a synthetic resin powder on the optionally preheated metal mesh is applied and formed from foil, metal mesh and dispersion application Laminate to gelation or solidification of the applied vinyl resin and the union of which with the foil is subjected to a heat treatment. Considered publications: German Patent Specifications No. 830 416, 970 339, 853 820.